1. Field of the Invention
This invention relates to a communication device to facilitate the communication abilities of speech-impaired individuals. In particular, the communication device is designed to offer those speech-impaired individuals with limited manual motor capacities the ability to communicate quickly and unambiguously.
2. Description of the Related Art
Communication between a speech-impaired individual and someone without this handicap is generally difficult and frustrating for both parties. Communication must be quick and accurate to avoid frustration on the part of the communicating parties. While sign language satisfy both of these requirements, it presents other disadvantages. Like any language it has a learning curve and is thus more suited for speech-impaired individuals who has had this impediment since an early age. Also, it requires learning on the part of the non-handicapped person or an interpreter. Lastly, speech-impaired individuals with limited manual motor capacities, such as amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease) patients, may not be capable of the vigorous gesturing involved in sign language.
There are several devices on the market to facilitate communication by a speech-impaired individual but they all fall short in terms of either quickness or accuracy. One device in the prior art has the user arranging tiles with symbols into a pictorial sentence. Such a device presents an inevitable tradeoff between quickness and accuracy; a small set of tiles would not adequately portray many concepts, while a large set of tiles would be cumbersome to manipulate. Also, speech-impaired individuals with limited manual motor capacities may lack the dexterity to use this device.
Another device has the symbols arranged in a circle with a pointer projecting from the center of the circle. A lever controlling a ratcheting mechanism moves the pointer to the next symbol in either a clockwise or anti-clockwise direction. However, the same limiting tradeoff between quickness and accuracy is readily discernible in this setup.
Yet another communication device has an aperture through which an observer can follow the eye movement of a speech-impaired individual to determine a symbol or an alphabet on a chart that the latter is viewing. This method is prone to observer error and thus unreliable. Also, this device allows the speech-impaired individual to communicate with only one other person.
The ALS society has a laptop computer with an input device that detects an ALS patient's eyelid movement. A patient uses this device to manipulate a pointer over a chart displayed on the laptop's screen. Unfortunately this input device has two shortcomings that make it difficult to use. First, its lengthy calibration process means that even a relatively simple communication, such as requesting a sip of water, must be burdened with a huge time overhead. Second, natural movements of the patient's head easily upsets its calibration. As a result, the detection is rather erratic.
Accordingly, there is a need for a communication device for speech-impaired individuals to quickly and accurately communicate their needs and desires. To achieve this end, such a device must be intuitive, both for the speech-impaired individual to use, and for the non-handicapped person to comprehend. There must be no significant time overhead due to calibration. Also, this device must be capable of being operated by those handicapped individuals with limited manual motor capacities to maximize its range of applications. These are the objectives of the present invention.